The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Aerial vehicles are utilized in increasingly diverse applications such as, for example, air and surface combat, reconnaissance, logistics, research, and rescue applications. Aerial vehicle designs include very diverse shapes, sizes, configurations and characteristics, wherein each of the different aerial vehicle designs can be optimized for one or more specific application. For certain applications, fuel cell powered aerial vehicles are highly desirable because fuel cells provide a robust, low vibration, low emission, high-energy density power source for the aerial vehicle. Therefore, fuel cell powered aerial vehicles can operate for extended time period and over extended distances. Further, aerial vehicles utilizing fuel cells produce low noise level and low thermal signatures, which makes detection difficult.
Aerial vehicles can utilize hybrid fuel cell power systems comprising a fuel cell and a secondary battery. Both the secondary battery and the fuel cell are electrically coupled to a power bus supplying power to system components of the aerial vehicle. The fuel cell can continuously convert stored fuel to electrical power to the power bus at high energy efficiencies. The secondary battery can provide electrical power to the power bus by discharging the secondary battery and can receive electrical power from the power bus to charge the secondary battery.
Fuel cell power and battery power can be actively managed to efficiently power components of the aerial vehicle including the propulsion module, the system control, sensing components, and payload components of the aerial vehicle. For example, the secondary battery can be discharged to meet short-term component power requirements; however, typically much less energy is stored as battery charge than is stored as fuel supplied to the fuel cell. Therefore, while the secondary battery can be discharged to power aerial vehicle components for short periods of time, when the rechargeable battery is discharged over extended periods of time the battery state-of-charge will drop to a lower state-of-charge limit making battery power unavailable.
Therefore, new autonomous and manual methods for efficiently controlling power and energy within aerial vehicles are needed.